Thin layer chromatography, referred to in laboratory parlance as TLC, has become an increasingly useful tool for detecting tiny amounts of drugs in specimens. The analysis procedure involves the extraction of drugs from biological fluids by passing the specimen or drug-containing fluid through a chromatography or adsorption column containing a packing medium. The drugs are eluted from the column by an appropriate organic solvent which is then evaporated, to concentrate the drugs. In a second procedure the concentrated residue is redissolved in a few drops of solvent which is transferred as a spot onto the chromatography plate. THe deposition is dried, and thereafter the plate is activated with solvent to initiate the detectable migration patterns on the plate surface thus revealing the identity of the compounds or drugs contained in the specimen. In this fashion urine samples are screened for barbituates, opiates, amphetamines and other narcotics. Equipment and techniques heretofore available have made the screening of multiple samples both expensive and time-consuming.
The present invention has for its object to provide a new design for an applicator and an application and column assembly which will allow the direct application of the column eluate to a chromatography plate with the eluate drying in a small spot as it reaches the plate surface.